The present invention relates to a vehicle tire having at least one carcass ply extending between bead regions, a tread region and a belt arrangement disposed between the carcass and the tread as well as a tread profile or pattern provided in the tread region having at least one overwide circumferential groove disposed in particular away from the middle and on the inner side of the tire.
In the design of tread profiles or patterns in the tread region of pneumatic tires for vehicles, it can be of advantage for a variety of reasons, particularly for reasons of tire noise minimization or also to improve the aquaplaning properties, to provide at least one particularly wide groove extending over the tire circumference which can be straight or also with waves and the like. The width of such a groove can be, for example, a 30 mm or more. However the use of such grooves in a tread profile can lead to a structural weak spot at which, when the tire is in use, an unwanted, higher growth can occur if special measures are not taken.
It is the object of the present invention to design a vehicle tire of the initially named kind in such a way that, on the one hand, the advantages arising from the use of overwide circumferential grooves can be used to the full and, on the other hand, weak spots resulting from the existence of such grooves can be avoided and even additional advantages can be achieved with regard to the properties of the respective tire.
Accordingly the object of the present invention is generally satisfied in that the tire region disposed beneath the overwide circumferential groove, which has, in particular, a width of more than 30 mm, is provided with additional localised reinforcement in the axial direction.
In accordance with a preferred embodiment of the present invention, the particularly wide groove is located on the respective inner tire side, and only such circumferential grooves which do not lead to any structural weak spots in the tire construction are located on the outer tire side.
The additional localised reinforcements to be provided beneath the overwide groove can be realised in different manners in accordance with the present invention, with the possibility of combining different solutions also existing.
A first version for the provision of the a required local reinforcement includes the use of at least one additional winding bandage, in particular using a nylon strip, or an additional strip consisting of an essentially non-extensible material, in particular an aramide, beneath such a winding bandage. An asymmetrical tire construction is thus created which leads to specifically pre-determinable tire properties.
Another possibility of providing a reinforcement in the region beneath the circumferential groove includes the designing of a belt ply arrangement in such a way that cord plies, in particular steel cord plies, are used beneath the weak spot created by the groove, such cords extend at a less steep angle towards the direction of the periphery than in the remaining region of the overall belt ply arrangement. This principle can be particularly realised advantageously using part belts. In this way, for example, unwanted growth of the tire on the inner tire side, where the overwide groove is positioned, can be avoided at high speeds, while cords are used on the outer tire side which extend towards the circumferential plane at a lower angle, whereby the handling properties of the tire can be improved.
In accordance with another embodiment of the invention, a folded belt arrangement is used in which at least one unfolded steel cord ply is enclosed at least at one side by a folded ply consisting, for example, of an aramide, in such a way that the turned-over end of the fold extends so far in the direction of the tire center that it spans the region below the groove.
Further possibilities of providing corresponding reinforcement comprise arranging a circumferential rubber strip having a high modulus beneath the groove and preferably directly adjacent to the carcass and/or drawing the turned-over end of at least one carcass ply so far upwards in the direction of the tire center and in contact with the carcass ply assembly that said carcass ply end extends over the region beneath the groove. Moreover, the groove base can be, alternatively or additionally, designed to increase stability, for example by means of a convex base shape or by means of a special structure, in particular in the form of angular or rounded elevations projecting in the direction of the circumference.